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 ###Instrução: Quando David McNamara foi o oponente na final, qual era o nível?
 ###Tabelas: CREATE TABLE buildings (buildings_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Building VARCHAR, Address VARCHAR, Height VARCHAR, Storeys INT, Completed INT) CREATE TABLE internet_availability (internet_availability_id AUTO_INCREMENT PRIMARY KEY, Nation VARCHAR, Population (thousands) INT, Internet subscriptions (2000) (thousands of users) INT, Internet subscriptions (2008) (thousands of users) INT, % growth (2000–2008) INT, % Internet users INT) CREATE TABLE missouri_counties_ranked_by_per_capita_income (missouri_counties_ranked_by_per_capita_income_id AUTO_INCREMENT PRIMARY KEY, County VARCHAR, Per capita income VARCHAR, Median household income VARCHAR, Median family income VARCHAR, Population INT, Number of households INT) CREATE TABLE world_championship_grand_prix_wins_by_engine_manufacturer (world_championship_grand_prix_wins_by_engine_manufacturer_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Engine VARCHAR, Wins INT, First win VARCHAR, Latest win VARCHAR) CREATE TABLE singles_wins (singles_wins_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Tournament VARCHAR, Tier VARCHAR, Surface VARCHAR, Opponent in the final VARCHAR, Score VARCHAR)  
SELECT Tier FROM singles_wins WHERE Opponent in the final = david mcnamara